how to control dc motor by pwm????

Ai Lim · Joined: 09 Apr 2013 Posts: 2 Location: malaysia

i have a question~~~

now i am doing my project but my coding is very poor~~

i wanna ask that how to control dc motor by pwm?? and i need control my motor move forward, backward, turn left and turn right~~

i use PIC18F2331, 2 L293DD half bridge driver(because i need control 4 dc motors), crystal 20M, my dc motor is 3volt each~~~

hope someone can help or guide me solve the problem~~~~

SherpaDoug · Joined: 07 Sep 2003 Posts: 1640 Location: Cape Cod Mass USA

Start out by studying the example programs ex_pwm.c and ex_power_pwm.c. Also read the PIC datasheet sections on the PWM capabilities of your chip.
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asmboy · Joined: 20 Nov 2007 Posts: 2128 Location: albany ny

you should also determine if you need a PWM DC modulator ( with filter) - or if you can safely direct switch the motor. ( a circuitry question )

understand that direct switching , while very simple, can cause harmful levels of RFI /EMI to other electronics in your vicinity.

branko · Joined: 26 Mar 2013 Posts: 8 Location: Russia

Generate PWM and use a button to increment or decrement a variable from 0 to 255. Use this variable's value to set the duty cycle of PWM signal. If your MCU gives 5V o/p then you need to bring the PWM voltage to 3V before giving it to the motor.
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